Process of concentrating ores.



PATENT OFFICE.

. UNITED sTATEs WAL ER MURRAY SANDERS, or MARION, KENTUCKY.

PROCESS OF GONCENTRATING ORES.

Patented Apr. 4, 1911. Renewed September 9, 1910. Serial To all whom it may concern: I

Be it known that I, "WALTER MURRAY SANDERS, a citizen of the United States, residing at Marion, in thecounty of Crittenden and State of Kentucky,- have invented certain new and useful In'iprovements in Processes-of Concentrating Ores, of which the following is a specification. This invention is a process of concentrating ores, and consists essentially in subjecting the ores to a preliminary purification or mechanical concentrationto separate therefrom certain components which I have found to exert a prejudicial efiect upon the separation by the so-called .fiotatlon process l, or upon the solutions employed therein; and thereafter subjecting the purified or partially concentrated.ores to treat- Inent'by flotation to effect a further concentration thereof, Y

I have discovered that when sulfid ores con-taininga considerable proportioh of a carbonate, such as calcite, are directly concentrated by the flotation process, in a solution adapted to react upon the ore to produce bubbles and capable of reacting upon calcite, a decomposition or alteration occurs in the solutionwhich reduces its eflicicncy and in time necessitates its renewal or replacement;

and that such decomposition or alteration occurs both 1n the use of acid solutions, and

in the use of nonacid solutions in accord aucc with my Patent 805,382, issued November 21, 1905. I have further discovered that the preliminary separation of the calcite,

.- and-ofsuch other components of relatively low. specific gravit as are usually eliminatcd' with. the calc1te, does'not exert an injurious cifect upon the subsequent separation by means of acid or non-acid solutions, but that by means of such .prelnninary purlfication the cil'ective ife of the 'solutions .isindefinite] y prolonged.

I Iwill describe my invention by reference to an ore containing as its principal components the minerals sphalerite, galena, flu.- orite, calcite and quartz. This ore in a suit; able state of subdivision is first purified or coin'eutrated, preferably by runningthe same over tables in. such nianner as-to efiect a separation of substantially all of the calcite, together with part or all of the silica, leaving a table concentrate consisting substantially of sphalerite, galena and fluorite, *with perhaps a small proportion of silica. This concentrate is then further treated'bj";

flotation, a non-acid solution being prefer ably employed in accordance With the corn ditions set forth in my patent above referred to. Substantially all of the sphalcrite is thus recovered.

I do not limit myself to any particular form of apparatus for the treatment of the ore, nor to any particular solution for conlcentrating the same by flotation.

I claim 1'. The process of concentrating sulfid ores. which consists in first concentrating the ore to effect a substantially complete separation of calcite, and thereafter subjecting the purified ore to further concentration by' flotation in a solution. adapted to react upon and capable of 

